300 Million Year Old Shark Jaw Bone Found in Kentucky Mine

The 300-million-year-old shark jawbone found by a Kentucky miner is being compared to a great white shark and probably weighed a couple of tons, experts said today.

The shark jaw was found Feb. 25 by Jay Wright, 25, of Dixon, Ky., a continuous miner operator for Webster County Coal.

Wright told ABC News that he was filling in for a sick coworker that day, adding supports to a roof 700 feet underground in the Dotiki Mine, when a half-inch thick rock fell from the roof. When he looked up, he saw the fossil.

"I could tell there was a bunch of teeth and [something] similar to a jaw," he said. "It was grayish in color with a shine -- so slick."

Wright said the jawbone was hanging from the roof, so he grabbed it. He pried more rock away and found two more pieces of jawbone. There was more, but he couldn't reach it. That area of the mine has since been sealed off, Wright said.

Still underground, he showed it to a few men in his mining unit before storing it in his tool box.

"They were surprised. They'd never seen something like that," Wright said.

Fearing that his three young children would break it if he took the jawbone home, Wright left it in an office at the mining site.

A month later, Jerry Weisenfluh, the associate director of the geological survey at the University of Kentucky, met Wright and saw the fossil after a colleague of his who also worked for Webster County Coal emailed him pictures.

The jawbone belongs to a shark from the Edestus genus, Weisenfluh said. He said that there was "an awful lot of interest" from the campus and the general public, which now can view the fossil at the college's Mines and Minerals Building.

The largest portion is 18 inches long; the other two are 5 inches to 6 inches long. The jaw is curved, not straight, and the teeth are 2 inches wide at the base of the jawbone and 2 to 2.5 inches high. Weisenfluh said the entire length of the jawbone was likely 30 inches. The teeth and their alignment are very well preserved.

Unlike modern sharks, which shed teeth during their lifetime, the Edestus shark had a permanent set, much like humans. He said its diet consisted mostly of soft-bodied fish and the shark's terrain likely evolved from a swampy area with tall trees and lush vegetation to a shallow sea similar to the Gulf of Mexico.

Modern Great White Shark

Weisenfluh said that he and the other researchers were very impressed with the specimens. He told ABC News today that from the size of the teeth, "this animal would have been comparable to a modern great white shark, weighing a couple of tons. It would be a big animal."

Although four or five Edestus fossils have been found in underground coal mines in the area since the 1950s, they have been much smaller, with smaller teeth and jawbones. He said that the sizes might represent the different ages of the Edestus and that the recent jawbone appeared to come from a full-grown adult.

"It's a pretty unusual find," he said. "We find lots of fossils in underground mines [but] this is pretty rare for us."

Before the fossil is returned to him in a month, Wright gave researchers permission to analyze its bone structure. Weisenfluh said he looks forward to the rare opportunity to study the fossil.

"This may contribute to understanding what this particular animal looked like 300 million years ago," he said.

Wright said he'd been contacted by people with personal collections who were interested in buying the fossil. For now he has no plans for the jawbone. He said he might display it at his family's drug store, where his wife is a pharmacist.